1. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 Ultrafast Laser Interactions with atoms, molecules, and ions Jarlath McKenna Supervisor: Prof. Ian Williams

2. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 The Experiment…. QUB Ion Beam Apparatus

3. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 The Experiment…. QUB Ion Beam Apparatus

4. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 The Experiment…. QUB Ion Beam Apparatus B Ions Magnet Aperture

5. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 The Experiment…. QUB Ion Beam Apparatus

6. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 The Experiment…. QUB Ion Beam Apparatus

7. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 The Experiment…. UCL Neutral Target Apparatus Focussed Laser Beam

8. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 and scanning techniques…. z x y Intensity Scan focussed laser direction ion beam direction

9. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 and scanning techniques…. z x y Intensity Selective Scan focussed laser direction ion beam direction

10. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 and scanning techniques…. z x y Intensity Selective Scan focussed laser direction ion beam direction

11. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 and scanning techniques…. z x y Intensity Selective Scan focussed laser direction ion beam direction

12. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 and scanning techniques…. z x y Intensity Selective Scan focussed laser direction ion beam direction

13. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 and scanning techniques…. z x y Intensity Selective Scan focussed laser direction ion beam direction

14. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 …Sequential ionization Walker et al PRL, 73, 1227 (1994)

15. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 S …Sequential ionization Walker et al PRL, 73, 1227 (1994)

16. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 S NS …Nonsequential ionization Walker et al PRL, 73, 1227 (1994)

17. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 S NS …Nonsequential ionization Walker et al PRL, 73, 1227 (1994)

18. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 Z Position (mm) Signal (arb.) Linear Circular …Xe results!! Xe → Xe +

19. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 Z Position (mm) Signal (arb.) Linear Circular …Xe results!! Xe → Xe +

20. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 Signal (arb.) Z Position (mm) Signal (arb.) Linear Circular …Xe results!! Xe → Xe 2+ Xe + from Xe

21. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 Signal (arb.) Z Position (mm) Signal (arb.) Linear Circular …Xe results!! Xe → Xe 3+ Xe + from Xe Xe 2+ from Xe

22. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 Signal (arb.) Z Position (mm) Signal (arb.) Linear Circular …Xe results!! Xe + → Xe 3+ Xe 2+ from Xe Xe 3+ from Xe Xe + from Xe

23. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 Signal (arb.) Z Position (mm) Signal (arb.) Linear Circular …Xe results!! Xe 2+ → Xe 3+ Xe + from Xe Xe 2+ from Xe Xe 3+ from Xe Xe 3+ from Xe +

24. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 Signal (arb.) Z Position (mm) Signal (arb.) Linear Circular …Xe results!! Xe + → Xe 2+ Xe + from Xe Xe 2+ from Xe Xe 3+ from Xe Xe 3+ from Xe + Xe 3+ from Xe 2+

25. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 Vibrational Trapping in H 2 + ? 0  1  2  3  1s  g 2p  u Internuclear separation R (a.u.) 12345678910 0 -2 -3 -4 -5 Field-dressed potential energy (eV) v = 0 v = 9 v = 5 v = 4 v = 3 H neutrals from H 2 +

26. Intense Field Femtosecond Laser Interactions AMP TalkJune 2004 …So what’s next?? Position Sensitive Detector resolve vibrational levels of H 2 + Cool vibrational levels of H 2 + electrostatic ion trap electric quadrupole Shorter pulses (~10 fs) hollow fibre (gas cell) freeze vibrational motion Frequency double laser (i.e. 800nm → 400nm) larger shift of photon dressed states of H 2 +